The present invention relates to an image sensing apparatus and method which senses an image of an object and, more particularly, to an image sensing apparatus and method which stores a plurality of images obtained by sensing an object.
In a conventional image sensing apparatus, such as a video camera for sensing images used for TV, its resolution is not high enough to handle a still image of high definition. The number of effective pixels inputted from a typical video camera is about 400,000 per screen. Further, an image sensed by the video camera is generally outputted as standard video signals (e.g., NTSC, PAL, SECAM).
Therefore, in order to obtain a high quality still image by using a conventional video camera, a method in which an entire image to be inputted is divided into a plurality of sections, an image for each section is inputted, then the plurality of inputted image sections are combined to constitute a single still image of high quality is used.
Referring to FIG. 22, a configuration and an operation of a conventional image input apparatus will be described below. Reference numeral 1 denotes a camera unit for sensing images of a person, document, picture, and the like; 2, a camera controller used for changing image sensing area of the camera unit 1; 3, an input image processing unit for converting image signals inputted from the camera unit 1 to image data so as to be used for various purposes; 4, a memory input controller for designating memory area and controlling timing when inputting the image data which is outputted from the input image processing unit 3; 5, a memory for temporarily storing the image data; 6, a memory output controller for designating memory area and controlling timing when reading image data from the memory 5 and for transmitting the read image data to a main controller 7; 7, the main controller for controlling entire processing since the image is inputted, processed and outputted; 8, a storage unit for storing image data; 9, a display for displaying image data; 10, an output unit for printing image data; and 11, a communication unit for sending/receiving image data to/from other terminal.
Next, an operation of the aforesaid configuration for inputting a high definition image is described below. In the operation, an image area to be sensed is divided into a plurality of sections, and the divided image sections of the image are sequentially inputted, then the inputted image sections are combined to reproduce a single still picture of high quality.
First, the camera controller 2 controls the camera unit 1 in accordance with designation from the main controller 7 so that the image sensing area of the camera unit 1 is set at a desired position. Next, image signals inputted by the camera unit 1 enter the input image processing unit 3, and converted into image data.
If the image signals are composite signals, such as NTSC and PAL, then the input image processing unit 3 separates the signals into Y signals (luminance signals) and C signals (color difference signals), further performs color difference separation on the C signals to separate the signals into Cr and Cb signals. The obtained Y signals, Cr signals, and Cb signals are then A/D converted. Further, if color space conversion is necessary, the signals are processed with color space conversion so as to be changed into R (red) signals, G (green) signals, and B (blue) signals. Furthermore, if format conversion, resolution conversion, or enlargement/compression process is necessary, then the signals are processed with a pixel density conversion and related interpolation which is performed by using filters or the like.
As described above, the processed image data is stored in an area, designated by the memory input controller 4, of the memory 5.
By repeating the aforesaid operation as many times as the number of the divided sections, all the image data of the entire image sensing area is stored in the memory 5.
Thereafter, the image data of each section is combined and composed, thereby obtaining image data for a single still image of high resolution. If the high resolution still image is to be outputted on a paper sheet, then the main controller 7 transmits the image data to the output unit 10 where the image is outputted. Further, if the still image is to be stored, then the main controller 7 transmits the image data to the storage unit 8 and store it. Furthermore, if the still image is to be displayed, then the main controller 7 transmits the image data to the display 9 where the still image is displayed, and if to be transmitted to another device placed at distance or to other terminal, then transmits the image data to the communication unit 11 where the image data is transmitted to outside.
FIGS. 23 and 24 are flowcharts showing the aforesaid operation.
Specifically, FIG. 23 shows a case of inputting a still image of high resolution, whereas FIG. 24 shows a case of outputting a still image of high resolution.
Referring to FIG. 23, first, whether or not inputting a still image is determined (S231). If it is not, then a moving image is inputted from the camera unit 1 (S243), and the input moving image is transmitted to the display 9 and displayed there.
In a case of inputting a still image, resolution for inputting the still image is set (S232). In an example, image sensing ability of a typical video camera in an image sensing area is 768 pixels in the horizontal direction and 494 lines in the vertical direction in a case of NTSC, and 752 pixels in the horizontal direction and 582 lines in the vertical direction in a case of PAL. The resolution of the video camera can be obtained by dividing the image sensing ability by the size of the image sensing area.
Since it is possible to improve resolution, as described above, by inputting an image portion by portion, the number of sections into which an image sensing area is to be divided (referred as "frame division number" hereinafter) is set in order to input a still image of higher resolution than the resolution based on the aforesaid image sensing ability (S234).
Next, an image inputting process will be described.
First, the camera controller 2 controls the camera unit 1 to sense an image section, the first section, of an image sensing area divided on the basis of a frame division number (S237).
Thereafter, the image section, the first section, is inputted by the camera unit 1 and processed by the input image processing unit 3 (S238). Then, the processed image data is stored in a designated area of the memory 5 by the memory input controller 4 (S239).
The aforesaid image input process is repeated as many times as the frame division number (S240). Note that the section of the image sensing area to be sensed as well as an area in the memory 5 used for storing image data are changed in each image input process.
When the image in the designated image sensing area has been entirely sensed by sections, the still image input process is completed (S241).
If another still image or moving image is to be inputted, the process is continued, whereas if not, the process is terminated (S242).
Next, referring to FIG. 24, when the still image inputted by performing the aforesaid operation is to be outputted, whether or not the still image is to be printed is determined (S251). If the still image is to be printed, then image data of a designated still image stored in the storage unit 8 is transmitted to the output unit 10 where the image is printed on paper (S252).
Next, whether or not the image is to be displayed is determined (S253), and if it is, image data of a designated still image stored in the storage unit 8 is transmitted to the display 9 where the image is displayed (S254). It should be noted that the image is displayed on a CRT and the like.
Next, whether or not the image is to be transmitted is determined (S255). If it is, then image data of a designated still image stored in the storage unit 8 is transmitted to the communication unit 11 where the image data is transmitted to a communication unit of destination (S256).
If there is another output request, the process is continued, whereas, if there is not, the process is terminated (S257).
In the aforesaid conventional apparatus, it is possible to input a high quality still image, and store, display, output, and/or transmit it.
However, if it is desired to partially make some addition, deletion, and/or exchange on the input still image, it is necessary to entirely input another high quality still image.
Further, since a still image which is similar to a previously input still image is newly inputted as described in the previous paragraph, the still image inputted previously and the still image being inputted currently are dealt with separately, with no recognized relationship between them.
In other words, although plural sets of information for the plural still image are almost same, it is necessary for a memory to have enough capacity to store the all sets of the information. Accordingly, a problem in increase storage requirement to store two or more almost identical still images exists.
In addition to storing the image data, in a case of transmitting the almost identical still images, all the image data is to be entirely transmitted, thus wasting transmission time.